Rules are quite simple use this guide. (contest closed 2009)

Your grandma tells you that you're the devil and you LOL all the time, but here is your chance to prove it. Think Atheist is challenging you to create the best atheist Halloween costume!

The winner of the contest will get a free t-shirt (from one of the TA stores) or anyThink Atheist Amazon book with with their entry and will be promoted on the home page. :] 2nd and 3rd place get TA bracelets :]